The proposed research is designed to explore the relationship between infections and pregnancy. Normal and high-risk pregnancies will be studied. We are particularly interested in studying the peroxidase-H2O2-C1 minus antimicrobial system in our total population and in different stages of gestation. Sources of peroxidase other than peripheral blood leukocytes will be included in our study. BIBLIOGRAPHIC REFERENCES: Sbarra, A.J., Selvaraj, R.J., Paul, B.B. and Mitchell, G.W., Jr. Normal and abnormal biochemical and antimicrobial activities of leukocytes. The Reticuloendothelial System: IAP Monograph No. 16, 1975, pp. 37-48. Sbarra, A.J., Selvaraj, R.J., Paul, B.B. Zgliczynski, J.M., Poskitt, P.K.F., Mitchell, G.W., Jr. and Louis F. Chlorination, decarboxylation and bactericidal activity medicated by the MPO-H2O2-C1 minus system. Advances in Experimental Medicine and Biology, 1976. (In press).